A small, fairly inexpensive device called a UDRC-II that is available from Northwest Digital Radio at http://nwdigitalradio.com is what makes the repeater work as an analog FM, C4FM Fusion or D-STAR repeater. The UDRC-II’s 40-pin connector plugs directly into the pins on a $35 Raspberry Pi 3.
For $89, the UDRC-II comes with a cable that is ready made for the DR-1X Yaesu repeater and the UDRC-II. As soon as you plug it into the repeater and turn it on, the UDRC-II and Raspberry Pi “light up,” take over the controller duties from the DR-1X’s built-in controller, and set the mode of the Yaesu repeater to “AUTO.”
When an analog FM signal comes in, it lets the repeater’s internal controller take over and the repeater operates just as it always has receiving and re-transmitting a standard FM signal.
When a D-STAR signal comes into the repeater, the UDRC-II’s controller takes over and shifts the mode of the repeater from “AUTO” to “FIX” as shown on the repeater’s front panel. You hear no audio through the repeater’s speaker and the repeater’s microphone doesn’t work. About 2 or 3 seconds after a D-STAR transmission ends, the repeater shifts back to “AUTO” mode. It’s actually pretty cool to watch it work!
I’m still working on this “new system” being able to connect to world-wide reflectors. The main problem with that is I’m not very good with Linux, so I’m challenged trying to get the Raspberry Pi connected to the Internet. I’ve played with my modem, router, the “Pi,” etc. I’ll get it. The guys at NW Digital are terrific and are spending a lot of their time helping me.
FM stations cannot communicate with D-STAR stations, but the two modes (plus Fusion) coexist very nicely on this one repeater as long as two ops on D-STAR don’t try to communicate at the same time as two ops on FM.
By the way, when a D-STAR conversation is going on on the 444.1 repeater, analog FM users hear nothing – and vice versa. The only indication of a conversation in a different mode from yours is that the signal strength meter on your transceiver will show transmit power from the repeater. So, a person with an analog FM transceiver tuned to 444.1 wouldn’t even know that an entire 10 or 15 minute D-STAR conversation had happened on 444.1 unless he had looked down at his transceiver’s signal strength meter!